Precast concrete silo complex and a method of constructing it

Abstract

A precast concrete silo complex and a method of constructing it, in which quarter-cylindrical precast concrete members, constituting unit members, are each provided with a pair of radially protruding couplings near both the ends of the member, and the unit members are arranged to form unit cylinders. The unit cylinders are arranged lengthwise and crosswise, with the couplings facing the couplings of adjacent unit cylinders for defining a coupling space between each two adjacent unit cylinders. Horizontal clamp rods extend through the coupling spaces between the end portions of the unit members and between the couplings, and concrete is provided in the coupling spaces. The horizontal clamp rods are tensioned to clamp the end portions of the unit members and the couplings, to give prestress to the concrete, thereby combining the adjacent unit cylinders and solidifying the unit cylinders arranged lengthwise and crosswise. The unit members are joined vertically by mortar, and vertical clamp rods extend vertically set the unit members and are prestressed to apply prestress to the assembled unit cylinders, solidifying the complex vertically. Thus silo cylinders having a desired height are provided which are solidified lengthwise and crosswise, and which the inside of the silo cylinders constitute the main silo spaces and the spaces formed among the adjacent silo cylinders constitute sub silo spaces.

We claim: 
     
       1. A precast concrete member for use in constructing a concrete silo complex having a plurality of side-by-side silos, said member having a quarter-cylindrical configuration for being arranged in end-to-end fashion to form a cylinder unit, said member further having radially outwardly projecting coupling elements integral therewith and extending the full height of said member, one of said coupling elements being disposed adjacent each end of said member and said member having an end portion extending from each of said coupling elements to the corresponding end thereof, said coupling element having an outer end surface adapted to face a like outer end surface of a coupling element on a member in a cylinder unit in an adjacent silo, whereby said coupling element and the end portion adjacent thereto, with the corresponding coupling element and end portion on the adjacent member in the cylinder unit and the coupling elements on the members of the cylinder unit of an adjacent silo, form a box-like space for receiving concrete, said coupling elements having means for receiving tie means extending across said box-like space between two adjacent coupling elements, and said marginal end portions having means for receiving tie means extending across said box-like space between the end portion and the end portion of the member in the adjacent silo. 
     
     
       2. A precast concrete member as defined in claim 1 in which said member has a lower edge with means thereon for nesting engagement with the upper edge of a like member positioned below said member, whereby one of said members can be stacked on another member to form a silo of a pile of said cylinder units; and said member having means to receive vertically extending tie means for prestressing the thus stacked members. 
     
     
       3. A precast concrete silo complex comprising: a plurality of side-by-side silos, each silo being constituted by a plurality of members each having a quarter-cylindrical configuration and arranged in end-to-end fashion to form a plurality of cylinder units, each member further having radially outwardly projecting coupling elements integral therewith and extending the full height of said member, one of said coupling elements being disposed adjacent each end of said member and said member having an end portion extending from each of said coupling elements to the corresponding end thereof, a plurality of said cylinder units being stacked on one another with said members vertically aligned to form the silo, each coupling element having an outer end surface facing a like outer end surface of a coupling element on a member in a cylinder unit in an adjacent silo, a coupling element and the end portion adjacent thereto together with a corresponding coupling element and end portion on the adjacent member in the cylinder unit and the coupling elements on the members on the cylinder unit of an adjacent silo forming a box-like space between each of the adjacent silos for receiving concrete; horizontal tensioned tie rods extending across each box-like space between coupling elements on adjacent members in a cylinder unit; further horizontal tensioned tie rods extending across each box-like space between end portions of members in adjacent silos; concrete filling said box-like spaces between each of the adjacent silos and being reinforced by said tie rods; and vertical tensioned tie rods extending through pluralities of said members in each silo which pluralities together constitute all of the members in said silos. 
     
     
       4. A precast concrete silo complex according to claim 3 in which the surface of said coupling members on at least some of said members has a recess therein opening into the box-like space defined thereby and which recess is filled with concrete. 
     
     
       5. A precast concrete silo complex according to claim 3 in which the surface of said end portions on at least some of said members has a recess therein opening into the box-like space defined thereby and which recess is filled with concrete. 
     
     
       6. A precast concrete silo complex according to claim 3 in which the surface of said coupling members and said end portions on at least some of said members has a recess therein opening into the box-like space defined thereby and which recess is filled with concrete. 
     
     
       7. A precast concrete silo complex according to claim 3 in which the top edge of each member has a groove therein and the bottom of the next higher member has a protrusion therein mating with said groove, and each member further has inserts therein for mounting adjusting supports thereon at a plurality of positions on the upper and lower portions of said member. 
     
     
       8. A method of constructing a precast concrete silo complex comprising: precasting a plurality of members each having a quarter-cylindrical configuration and having radially outwardly projecting coupling elements integral therewith and extending the full height of said member, one of said coupling elements being disposed adjacent each end of said member and said member having an end portion extending from each of said coupling elements to the corresponding end thereof, arranging a plurality of said members in end-to-end fashion to form a plurality of cylinder units, stacking a plurality of said cylinder units on one another with mortar therebetween and with said members vertically aligned to form a plurality of side-by-side silos with each coupling element having an outer end surface facing a like outer end surface of a coupling element on a member in a cylinder unit in an adjacent silo, a coupling element and the end portion adjacent thereto together with a corresponding coupling element and end portion on the adjacent member in the cylinder unit and the coupling elements on the members of the cylinder unit of an adjacent silo forming a box-like space between each of the adjacent silos, placing horizontal tie rods across each box-like space between coupling elements on adjacent members in a cylinder unit, placing further horizontal tie rods across each box-like space between end portions of members in adjacent silos, filling said box-like spaces between each of the adjacent silos with concrete, tightening said horizontal tie rods for prestressing the concrete, placing vertical tie rods through pluralities of said members in each silo, which pluralities together constitute all of the members in said silos, and tightening said vertical tie rods for prestressing said stacked cylinder units. 
     
     
       9. A method as claimed in claim 8 further comprising, during stacking of said cylinder units, placing suspending supports on the upper portion of each of said members in the uppermost cylinder unit on a partically erected silo, suspending a scaffolding frame from said supports, stacking the next higher cylinder unit on the partially erected silo, placing further suspending supports on members in said next higher cylinder unit, and then raising the scaffolding frame to said further suspending supports and suspending the scaffolding frame therefrom, and thereafter repeating said steps for moving the scaffolding frame stage by stage upward in the silo being erected. 
     
     
       10. A method as claimed in claim 9 further comprising, when the scaffolding frame reaches the top cylinder unit in the silo, fixing the scaffolding frame to the suspending supports on the top cylinder unit to serve as a roof frame, and placing roof slabs on said roof frame. 
     
     
       11. A method as claimed in claim 8 further comprising, during stacking of said cylinder units, placing suspending supports on the members of the cylinder unit one below the uppermost cylinder unit on a partically erected silo, suspending the lower part of a two stage scaffolding frame from said supports, the scaffolding frame having an upper floor which, when the lower part is suspended from said supports, will be adjacent the upper edge of the said uppermost cylinder unit, stacking the next higher cylinder unit on the partically erected silo, placing further suspending supports on the members of the cylinder unit which was formerly the uppermost cylinder unit, hanging lift cable supports with lift cables depending therefrom over the top edge of the cylinder which is now the uppermost cylinder unit, using lifting means on said scaffolding framework and engaged with said lifting cables to lift said scaffolding framework to the level of said further suspending supports, and suspending said scaffolding framework from said further suspending supports.